Hydraulic elevator.



No. 793,148. PATENTED JUNE 27, 1905. 0. E. OSGHGER.

HYDRAULIC ELEVATOR.

APPLICATION FILED JULY 5. 1904.

INVENTOR WITNESSES Patented June 27, 1905.

UNITED STATES PATENT OFFICE.

CHARLES E. OSCHGER, OF PITTSBURG, PENNSYLVANIA.

HYDRAULIC ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 793,148, dated June 27, 1905.

Application filed July 5, 1904. Serial No. 215.250-

T!) (0Z1 whom, it 'HI/II/Z/ concern.-

Be it known that 1, Cinemas E. Osoneen, of Pittsburg, Allegheny county, Pennsylvania, have invented a new and useful Hydraulic Elevator, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming part of this specification, in which the figure is a diagrammatic side elevation of my improved elevator.

My invention relates to the class of hydraulic elevators wherein the moving element of the cylinder lifts the cage through suitable wire ropes or flexible connections.

The object of the invention is to lessen repairs, lengthen the life of the system, and prevent disagreeable vibration when stopping the car.

Heretofore in such elevator systems when the valve is sharply closed the sudden stoppage of the water-flow is apt to cause a jumping action, which strains the elevator parts and causes the car to vibrate.

My invention is designed to overcome this difficulty; and it consists in providing a relief-valve which will open at a predetermined pressure and allow water to pass from the cylinder into an air-cushioning chamber, this chamber having a drain-pipe with a small inlet from the air-chamber, so that the water can flow out, preferably into the main exhausttank.

In the drawing, 2 represents the elevatorcar, the lifting-rope or flexible connection 3 for which passes over the pulleys 4 and 5, thence down and around the sheave 6, and thence upwardly to the fixed point 7. The sheave 6 is secured to the upper end of the piston-rod 8 of the hydraulic cylinder 9. which may be of ordinary form and provided with the usual supply and exhaust system. I have shown the inlet-water as entering the valvecasing 10 through a pipe 11, the valve having a stem 12 with three disks thereon fitting in the casing. The stem is connected in the ordinary manner to the car-lever. From the valve-casing the pipe 13 leads to the upper end of the hydraulic cylinder and the pipe 14 to its lower end.

On the pipe 13 is a valve-casing 15, containing a downwardly-seating valve 16, which is held to its seat by a spring 17 acting on the external portion of its stem, the spring-pressure being adjustable by nuts on the stem. From this valve-chamber, above the valve, the channel 18 leads into an air-chamber 19, and from the channel 18 a small drain-pipe 20 leads downwardly to the exhaust-tank 21 and is preferably provided with a hand-valve 22. The usual exhaust-pipe 23 leads from the lower end of the valve-casing into the exhaust-tank.

A suction-pipe 24 leads from the pipe 14 over and down to the lower part of the exhaust-tank. This pipe is provided with, a gravity check-valve 25, which allows water to pass from the exhaust-tank to the lower part of the cylinder below the piston, but prevents water passing therethrough in the opposite direction.

In the system shown the elevator is arranged to overbalance the resistance of the water and is raised by water forced into the cylinder above its piston. \Vith the valve in the position shown the elevator-cage is descending, the water flowingfrom above the piston down through pipe 13 and thence through pipe 14 into the cylinder below the piston. To lift the car, the valve is drawn upwardly to cut off the pipe 11 from the inlet, the water then flowing into the cylinder above the piston through pipe 13, while the water below the piston flows out through pipes 14 and 23 to the exhausttank. 1V hen the valve is suddenly closed to stop the car in lowering, if the slight further movement of the piston raises the pressure in the cylinder above a predetermined limit the excess pressure will lift the spring-pressed valve 16 and a small amount of water will flow into the air-cushioning chamber until the excess pressure is relieved. As the water passes out from above the piston into the cushioningchamber the suction below the piston will draw in a corresponding amount of water through the pipe 24 and check-valve therein. The excess pressure is thus relieved and cushioned and the water in the air-chamber drains back slowly through pipe 20 into the exhausttank.

The advantages of my invention result from the use of the combined pressure-valve and air-cushion, which coact to prevent the jars and strains on the elevator which produce the disagreeable jumping of the elevator-cage. With the form shown the cushioning action will take place at the stops of the elevator during its descent. If it is desired to cushion the stops during the ascent of the elevator, this may be provided for by duplicating the air-cushioning chamber and valve with a drain-pipe and the suction-pipe, these being reversed in position-that is, in such case the suction-pipe would lead from the top of the cylinder and the air-cushion would be attached to the lower part of the cylinder or water connections.

Many variations and changes may be made in the form of the hydraulic cylinder, the point of attaching the pressure-valve and aircushion, and the other parts'without departing from my invention.

I clairn 1. In a hydraulic elevator, a hydraulic cylinder, a relief-valve attached to its water connections, and an air-chamber to which the relief-valve leads; substantially as described.

2. In an elevator system, a hydraulic cylinder having an air-chamber connected to its water connections, a relief-valve between the water connections and air-chamber, and a drain pipe of relatively small area leading from the air-chamber connection at a point outside the valve; substantially as described.

3. In a hydraulic elevator, a hydraulic cylinder, a relief-valve attached to its water connections at one side of the piston, an air-chamber to which the relief-valve leads, and a water-supply pipe leading to the cylinder on the other side of the piston and arranged to sup ply water during the cushioning action; substantially as described.

In testimony whereof I have hereunto set my hand.

CHARLES E. OSCHGER.

Witnesses:

J OHN MILLER, H. M. CORWIN. 

